FAILED: patch "[PATCH] drm/i915/bdw: Add missing delay during L3 SQC credit" failed to apply to 4.7-stable tree

The patch below does not apply to the 4.7-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Imre Deak <[email protected]>
Date: Tue, 3 May 2016 15:54:19 +0300
Subject: [PATCH] drm/i915/bdw: Add missing delay during L3 SQC credit
programming
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BSpec requires us to wait ~100 clocks before re-enabling clock gating, so make sure we do this.

index 2422ac38ce5d..227cd2d395a9 100644
@@ -6738,6 +6738,12 @@ static void broadwell_init_clock_gating(struct drm_device *dev)
 	misccpctl = I915_READ(GEN7_MISCCPCTL);
 	I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
 	I915_WRITE(GEN8_L3SQCREG1, BDW_WA_L3SQCREG1_DEFAULT);
+	/*
+	 * Wait at least 100 clocks before re-enabling clock gating. See
+	 * the definition of L3SQCREG1 in BSpec.
+	 */
+	POSTING_READ(GEN8_L3SQCREG1);
+	udelay(1);
 	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
 
 	/*